Sheath-mounted arterial plug delivery device

ABSTRACT

A method of facilitating hemostasis of a blood vessel puncture. The method includes the steps of inserting a tubular device into a puncture in a blood vessel to establish access to the blood vessel, providing a vessel closure system around the tubular device, introducing a hemostatic material into a space between the tubular device and vessel closure system, and delivering the hemostatic material adjacent to the puncture to facilitate hemostasis of the puncture.

[0001] This application claims priority under 35 U.S.C. § 119 toprovisional U.S. patent application Ser. No. 60/218,431, filed Jul. 14,2000, which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

[0002] The present invention relates to a method and system forfacilitating hemostasis of a blood vessel.

BRIEF DESCRIPTION OF THE RELATED ART

[0003] Numerous arterial puncture closure devices are known in the priorart. These include many mechanisms, such as plugs, sutures,intra-vascular structures and more. While these prior art devices varyin size and theory, they all require placement of distinct closuredevices through a procedural sheath, sheath exchanges, or sheath removalprior to placement. By their very nature, these devices represent aseparate procedure for access site closure after access siteestablishment/maintenance. The decision to use these devices is oftenbased upon the instant availability of the device and competing demandfor the doctor's time at the moment of sheath removal.

[0004] An additional challenge of puncture closure devices comes whenthey are deployed many hours after access has been established. In thesecases, time and additional access site manipulation contribute topotential infection.

[0005] What is needed is a single device which establishes and maintainsaccess to a puncture site, and closes the access site upon thecompletion of a procedure. In this way, the closure of the puncture sitecould become a standard of care, not subject to device availability,competing demand for doctor time, or site infection due to delayeddeployment.

[0006] Accordingly, it would be desirable to provide a method and systemthat enable the user to access a blood vessel with a sheath that alsoincorporates a means for access site closure. Furthermore, uponcompletion of the interventional procedure, the closure device isdeployed to close the puncture and the sheath is removed.

SUMMARY OF THE INVENTION

[0007] The present invention provides an improved method and system forfacilitating hemostasis of a blood vessel puncture.

[0008] In accordance with one aspect of the present invention, a methodof facilitating hemostasis of a blood vessel puncture includes the stepsof inserting a tubular device into a puncture in a blood vessel toestablish access to the blood vessel; providing a vessel closure systemaround the tubular device; introducing a hemostasis promoting materialinto a space between the tubular device and vessel closure system; anddelivering the hemostatic material adjacent to the puncture tofacilitate hemostasis of the puncture.

[0009] In accordance with a further aspect of the present invention, amethod of facilitating hemostasis of a blood vessel puncture, the methodincludes inserting a procedural access sheath through a tissue tract andinto a puncture in a blood vessel; providing a vessel closure systemaround the access sheath and at least partially in the issue tract; andperforming a vascular procedure with the vessel closure system in thetissue tract.

[0010] In accordance with another aspect of the present invention, asystem for facilitating hemostasis of a blood vessel puncture, thesystem including a delivery cannula configured to be received around anaccess sheath; a hemostasis promoting material within the deliverycannula for facilitating hemostasis of a blood vessel puncture whendelivered adjacent to the puncture; a proximal stop for preventingproximal motion of the hemostasis promoting material within the deliverycannula when the access sheath is withdrawn proximally from the deliverycannula; and a pusher for delivering the sponge material from thedelivery cannula.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The invention will now be described in greater detail withreference to the preferred embodiments illustrated in the accompanyingdrawings, in which like elements bear like reference numerals, andwherein:

[0012]FIG. 1a is a perspective view of a first embodiment of a deliverycannula according to the present invention positioned for delivery of ahemostatic promoting material;

[0013]FIG. 1b is a perspective view of the delivery cannula of FIG. 1awith the access sheath being removed;

[0014]FIG. 1c is a perspective view of the delivery cannula of FIGS. 1aand 1 b with the hemostatic promoting material being ejected;

[0015]FIG. 1d is a perspective view of an alternative embodiment of adelivery cannula with a side staging chamber;

[0016]FIG. 1e is a perspective view of the delivery cannula of FIG. 1dwith the hemostatic promoting material in the delivery cannula;

[0017]FIG. 2a is a perspective view of a delivery cannula according toan alternative embodiment;

[0018]FIG. 2b is a perspective view of a delivery cannula according toan alternative embodiment;

[0019]FIG. 3a is a perspective view of a delivery cannula according toan alternative embodiment;

[0020]FIG. 3b is a perspective view of a delivery cannula according toan another embodiment;

[0021]FIG. 4a is a perspective view of a delivery cannula according toan another embodiment; and

[0022]FIG. 4b is a perspective view of a delivery cannula according toan alternative embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present invention provides an access system that enables theuser to access a blood vessel with a sheath that also incorporates ameans for performing site closure. Upon completion of the interventionalprocedure, the closure device is deployed to close the puncture and thesheath is removed.

[0024] As shown in FIG. 1a, an access system for facilitating hemostasisof a blood vessel includes a delivery cannula 10 positioned coaxiallyaround an access sheath 20, and a hemostatic promoting material 30within the delivery cannula 10 for facilitating hemostasis of a bloodvessel puncture when delivered adjacent to the puncture. In onepreferred embodiment, the hemostatic material 30 is a hydrated andcompressed sponge.

[0025] The delivery cannula 10 as shown in FIG. 1a is dimensioned suchthat its proximal end 12 can attach to the access sheath 20 at or nearthe access sheath proximal end 22, and such that the delivery cannula 10distal end 14 terminates proximal to the distal end 24 of the accesssheath 20. Further, the delivery cannula 10 incorporates an annularproximal stop 40 fitting slideably around the access sheath 20 andremovably within the delivery cannula 10. The proximal stop 40 ispositioned within the delivery cannula 10 such that its distal end 44defines the proximal boundary of a coaxial hemostatic material space 26.The proximal end 42 of the proximal stop 40 is positioned at or near theproximal end 12 of the delivery cannula 10. The proximal stop 40 mayinclude a proximal flange 46 to facilitate proper placement within thedelivery cannula 10.

[0026] While the hemostatic material space 26 described herein iscoaxial, it can be appreciated that many other configurations arepossible. The hemostatic material space 26 is defined by the outside ofthe access sheath 20 and the inside of the delivery cannula 10 and maybe continuous, discontinuous, symmetrical, or nonsymmetrical.

[0027] In one preferred embodiment as shown in FIG. 1a, the accesssystem is prepared by attaching the delivery cannula 10 to the accesssheath 20 as described above. The hemostatic material 30 is thenintroduced into the coaxial space 26 between the delivery cannula 10 andaccess sheath 20.

[0028] In another preferred embodiment, as shown in FIGS. 1d & 1 e thehemostatic material 30 is introduced into the coaxial space 26 byhydrating an absorbable sponge in a staging chamber portion 50 of thedelivery cannula 10 and advancing the sponge through a side port 48 ofthe delivery cannula into a delivery position surrounding the accesssheath 20. The hydrating of the absorbable sponge is performed with asyringe 90 and a syringe plunger 92. A removable distal stop or vent 52may be provided to help position the hemostatic material 30 within thesystem. Alternatively, the distal stop or vent 52 may be soluble and/orabsorbable such that it remains in place during advancement of thesystem into the vascular access site and then dissolves to allowdelivery of the hemostatic material. A distal stop or vent 52 of thistype may be made of gelatin, polyglycolic acid, or other suitablematerial known to one skilled in the art.

[0029] The system can then be placed much like an ordinary access sheath20 as shown in FIG. 1a. The removable distal stop or vent 52 is removed(if present) and the system is placed over a guidewire 54 and into thevascular access site such that the portion of the access sheath 20extending distally beyond the distal end of the delivery cannula 10extends through a vessel puncture 55 and into a vessel 57 and the distalend of the delivery cannula 10 resides at or near the outer blood vesselwall 58. A bleed-back hole 60 in the access sheath 20 can be utilized toprovide bleed-back as an indication that the distal end 14 of thedelivery cannula 10 is within a predetermined proximity with respect tothe blood vessel 58. The lack of bleed-back 62 indicates a more proximallocation of the delivery cannula 10. The delivery cannula 10 may bepositioned using only bleed-back 62 as an indicator of position, or maybe more precisely located by utilizing tactile feedback as the enlargeddistal end of the delivery cannula 10 encounters the outer blood vesselwall 58.

[0030] Bleed-back 62 is facilitated by providing a dilator 70 within theaccess sheath 20 that fits closely over the guidewire 54 at its distalend 74 such that it substantially prevents blood from entering thedilator 70. Further, the dilator 70 fits closely within the distalaccess sheath 20 such that it substantially prevents blood from enteringthe access sheath. In this way, blood is restricted from entering theaccess sheath 20 until the bleed-back hole 60 enters the blood vessel58. Blood entering the bleed-back hole 60 might then exit the patientthrough a number of paths.

[0031] If the access sheath 20 was provided with a seal at its proximalend 22, the blood might enter a hole in the dilator 70 and then exit theproximal end 72 of the dilator 70. Alternatively, blood could flowbetween the dilator 70 and access sheath 20 to an exit in theintroduction port 76 and stop-cock 78 as shown in FIG. 1 a. If theaccess sheath 20 has no proximal seal, the blood could exit the proximalend 22 of the access sheath 20.

[0032] In operation, the access systems of the present invention areused as follows. The interventional procedure is conducted as usual withthe delivery cannula 10 and hemostatic material 30 in place during theprocedure. At the end of the interventional procedure, the access sheath20 portion of the system is detached from the delivery cannula 10 andfully withdrawn while the delivery cannula 10 and proximal stop 40remain stationary as shown in FIG. 1b. The proximal stop 40 prevents thehemostatic material 30 from moving proximally during access sheath 20removal. This portion of the procedure may take place with or without aguidewire 54 in place.

[0033] The proximal stop 40 is then removed from the delivery cannula 10and a pusher 80 having an outside diameter just smaller than the insidediameter of the delivery cannula 10 is placed over the guidewire 54 (ifpresent) and advanced until it contacts the proximal portion ofhemostatic material 30. As shown in FIG. 1c, the hemostatic material 30is then delivered by moving the delivery cannula 10 proximally withrespect to the pusher 80.

[0034] In one preferred embodiment, the pusher 80 is held stationarywhile the delivery cannula 10 is withdrawn. It is also understood thatthe pusher 80 can be advanced while the delivery cannula 10 is heldstationary. It is further understood that any combination of thesetechniques can result in delivery of hemostatic material 30. Afterdelivering hemostatic material 30 into the desired site, the guidewire54 (if present) and the pusher 80 and cannula 10 are removed from thepuncture tract.

[0035] In an alternative embodiment, as shown in FIG. 2a, a proximalstop 40 is positioned within the delivery cannula 10 such that itsdistal end 44 defines the proximal boundary of the coaxial hemostaticmaterial space 26. The proximal end 42 of the proximal stop 40terminates at the proximal end 12 of the delivery cannula 10. Detent 86features such as bumps or ratchets may be included on the inside of thedelivery cannula 10 or the outside of the proximal stop 40 to releasiblyhold the proximal stop 40 in place. Upon completion of theinterventional procedure, the access sheath 20 portion of the system iswithdrawn while the delivery cannula 10 and proximal stop 40 remainstationary as shown in FIG. 2a. The proximal stop 40 prevents thehemostatic material 30 from moving proximally during access sheath 20removal. This portion of the procedure may take place with or without aguidewire 54 in place.

[0036] A pusher 80 shown in FIG. 2b, having a distal portion 83 with anoutside diameter similar to the previously removed access sheath 20 anda length similar to the proximal stop 40 is then placed over theguidewire 54 (if present) and advanced into the proximal stop 40 untilits distal end 84 is approximately aligned with the distal end 44 of theproximal stop 40. The pusher 80 may be provided with a proximal shoulder85 to facilitate this alignment. As shown in FIG. 2b, the hemostaticmaterial 30 is then delivered by moving the delivery cannula 10proximally with respect to the pusher 80 and proximal stop 40. In onepreferred embodiment, the pusher 80 and proximal stop 40 are heldstationary while the delivery cannula 10 is withdrawn. The pusher 80 mayinclude a proximal flange 88 to beneficially limit its movement withrespect to the delivery cannula 10. After delivering hemostatic material30 into a desired site, the guidewire 54 (if present) and system areremoved.

[0037] In an alternative embodiment, as shown in FIG. 3a, a longerproximal stop 40 is positioned within the delivery cannula 10 such thatits distal end 44 defines the proximal boundary of the coaxialhemostatic material space 26. The proximal end 42 of the proximal stop40 extends beyond the proximal end 12 of the delivery cannula 10 adistance equal to or greater than the length of the coaxial hemostaticmaterial space 26. Upon completion of the interventional procedure, theaccess sheath 20 portion of the system is detached from the deliverycannula 10 and fully withdrawn while the delivery cannula 10 andproximal stop 40 remain stationary. The proximal stop 40 is held inplace manually or with a locking mechanism to prevent the hemostaticmaterial 30 from moving proximally during access sheath 20 removal. Thisportion of the procedure may take place with or without a guidewire 54in place.

[0038] As shown in FIG. 3b, a pusher 80 having an outside diametersimilar to the previously removed access sheath 20 and a length similarto the proximal stop 40 is then placed over the guidewire 54 (ifpresent) and advanced into the proximal stop 40 until its distal end 84is approximately aligned with the distal end 44 of the proximal stop 40.The pusher 80 may be provided with a proximal flange to facilitate thisalignment. The hemostatic material 30 is then delivered by moving thedelivery cannula 10 proximally with respect to the pusher 80 andproximal stop 40 as shown in FIG. 3b. In one preferred embodiment, thepusher 80 and proximal stop 40 are held stationary while the deliverycannula 10 is withdrawn. The proximal stop 40 may include a proximalflange to beneficially limit its movement with respect to the deliverycannula. After delivering hemostatic material 30 into desired site, theguidewire 54 (if present) and system are removed.

[0039] In still another embodiment shown in FIG. 4a, a proximal stop 40similar to that just described is used to deliver the hemostaticmaterial without the use of a pusher 80. A system incorporating thistype of proximal stop 40 is placed within an access site. At the end ofthe interventional procedure and prior to access sheath 20 removal, thedelivery cannula 10 is moved proximally with respect to the proximalstop 40 as shown in FIG. 4a. In this way the hemostatic material 30 isdelivered to the desired site with the access sheath 20 still in place.The access sheath 20 provides hemostasis at the puncture site 98 duringhemostatic material 30 delivery and also prevents hemostatic material 30from entering the puncture site 98.

[0040] As shown in FIG. 4b, the delivery cannula 10 and proximal stop 40are then held stationary to stabilize the hemostatic material 30 whilethe access sheath 20 is removed. The delivery cannula 10 and proximalstop 40 can then be removed from the site. Note that the guidewire 54(if present) can be removed before the access sheath 20 is removed, whenthe access sheath 20 is removed, after the access sheath 20 is removed,or after the delivery cannula 10 and proximal stop 40 are removed.

[0041] Other means of positioning the hemostatic material within thesystem include placing the hemostatic material within the distal lumenof the delivery cannula 10 and then passing the access sheath 20 throughit.

[0042] In another preferred embodiment the hemostatic promoting material30 is placed in the cannula by placing a hydrated sponge within thedistal end 14 of the delivery cannula 10. The distal end 24 of theaccess sheath 20 with a stylet or obturator placed within it is thenadvanced into the proximal end 12 of the delivery cannula 10 and throughthe sponge until the distal access sheath 20 protrudes beyond the distalend 14 of the delivery cannula 10. The stylet or obturator is thenremoved to ready the system for placement into an access site.

[0043] The absorbable sponge material can be absorbed by the body in aperiod of time between several days and several months depending on theabsorbable sponge material used. A pledget formed of commerciallyavailable Gelfoam material will be absorbed by the body within 1 to 6weeks. However, the pledget material may be engineered to providedifferent rates of absorption. For example, Gelfoam can be designed tobe absorbed at different rates by varying the degree of cross-linkingPreferably, the pledget is designed to be absorbed in less than onemonth.

[0044] Although the invention is primarily intended for delivery ofabsorbable sponge, non-absorbable sponge may also be delivered with thedevices, systems, and methods of the present invention. A non-absorbablesponge may be desirable where it will be necessary to locate the bloodvessel puncture after the procedure.

[0045] While an amorphous or discontinuous sponge structure may be usedin the present invention, a continuous structure of the deliveredabsorbable sponge pledget provides more secure and reliable placement ofa plug of material against the blood vessel puncture than a paste orliquid. The continuous sponge structure can even facilitate partialwithdrawal, removal, or movement of the ejected pledget.

[0046] The absorbable sponge material can be hydrated with a clottingagent such as thrombin, a contrast agent, another beneficial agent, acombination of agents, or the like. Alternatively, the pledget materialitself may contain an agent such as a clotting agent, a contrast agent,another beneficial agent, a combination of agents, or the like.

[0047] The absorbable sponge pledget may be presoaked with a beneficialagent such as thrombin for delivery of the beneficial agent to thepunctured blood vessel. Alternatively, the pledget may be hydrated witha beneficial liquid agent used as the hydrating fluid within a syringe.Further, the beneficial agent may be delivered to the pledget after thepledget is ejected at the blood vessel puncture site through the lumenof the pusher 80, through the delivery cannula 10, through the accesssheath 20 or through the dilator 70.

[0048] Because the amount of subcutaneous fat and tissue between theskin 64 and the blood vessel wall 58 varies between patients fromapproximately 0.5 cm to 15 cm or more the system may be provided indifferent lengths for use in different patients. The pledget size andshape may also be varied for different patients. The absorbable spongematerial should form a complete plug over the puncture site withoutexpanding into the blood vessel or exiting the skin of the patient. Insome instances where the amount of subcutaneous tissue is great it maybe desirable to deliver multiple pledgets in spaced apart positionsalong the tract leading to the puncture site.

[0049] The particular size and shape of the access system may varydepending on the size of the access site, amount of subcutaneous tissue,and the size of pledget to be delivered. According to one example of thepresent invention, a pledget is formed from a rectangular piece ofpre-compressed Gelfoam approximately 2 by 3 cm with a thickness of 0.15cm. The Gelfoam is rolled or folded into a pledget having a length ofapproximately 3 cm. An introducer for delivery of this pledget to apatient with an average amount of subcutaneous tissue has a stagingchamber length of about 2.5 to 6 cm, preferably approximately 3 cm, astaging chamber inner diameter of about 0.12 to 1.5 cm, preferably about0.3 cm to about 0.6 cm, and a delivery chamber which is typically longerthan the staging chamber and has an inner diameter smaller than that ofthe staging chamber of about 1 cm or less, preferably approximately 0.33cm or less. The particular length of the delivery chamber depends onboth the subcutaneous tissue depth of the patient and the linearexpansion of the pledget as it moves from the staging chamber to thedelivery chamber. An angle made by a wall of the tapered section 38 witha longitudinal axis of the adaptor may vary from about 5° to 90°, but ispreferably between about 30° and 60°, more preferably approximately 45°.The tapered section 38 is illustrated with a substantially planarinterior surface, when shown in cross section. However, the taperedsection may also have a convex or concave surface in cross-section. Thisexample of pledget and introducer configurations is merely exemplary ofthe present invention.

[0050] In addition, the hemostatic promoting material 30 may be insertedinto the cannula in a dry form and hydrated in the cannula.Alternatively, the hemostatic material may be hydrated prior to stagingin the cannula, hydrated after delivery or any combination thereof.

[0051] While the invention has been described in detail with referenceto the preferred embodiments thereof, it will be apparent to one skilledin the art that various changes and modifications can be made andequivalents employed, without departing from the present invention.

1. A method of facilitating hemostasis of a blood vessel puncture, themethod comprising: inserting a tubular device into a puncture in a bloodvessel to establish access to the blood vessel; providing a vesselclosure system around the tubular device; introducing a hemostasispromoting material into a space between the tubular device and vesselclosure system; and delivering the hemostatic material adjacent to thepuncture to facilitate hemostasis of the puncture.
 2. The method ofclaim 1, further comprising a step of withdrawing the tubular deviceprior to delivery of the hemostatic material.
 3. The method of claim 1,further comprising a step of hydrating an absorbable sponge material ina staging chamber portion of the vessel closure system.
 4. The method ofclaim 3, further comprising a step of advancing the absorbable spongematerial into a delivery position.
 5. The method of claim 1, furthercomprising a step of locating the puncture by using a bleed-back hole inthe vessel closure system.
 6. The method of claim 1, further comprisinga step of the locating the puncture by using tactile feedback.
 7. Themethod of claim 1, further comprising a step of hydrating the hemostaticmaterial with a syringe.
 8. The method of claim 1, further comprising astep of positioning the hemostatic material within the system using adistal stop or vent.
 9. The method of claim 1, further comprising a stepof placing the tubular device and vessel closure system over aguidewire.
 10. The method of claim 1, further comprising a step offacilitating bleed-back by providing a dilator within the tubulardevice.
 11. The method of claim 1, further comprising a step of removinga proximal stop from the vessel closure system.
 12. The method of claim1, further comprising a step of advancing the hemostatic material with apusher and delivering the hemostatic material by moving the vesselclosure system proximally with respect to the pusher.
 13. The method ofclaim 12, further comprising a step of holding the pusher stationarywhile the vessel closure system is withdrawn.
 14. The method of claim12, further comprising a step of advancing the pusher while the vesselclosure system is held stationary.
 15. The method of claim 9, furthercomprising a step of removing the guidewire after the hemostaticmaterial is delivered.
 16. The method of claim 1, further comprising astep of removing the vessel closure system after the hemostatic materialis delivered.
 17. The method of claim 11, further comprising a step ofremoving the tubular device while the vessel closure system and proximalstop remain stationary.
 18. The method of claim 1, further comprising astep of advancing a pusher into the proximal stop and moving the vesselclosure system proximally with respect to the pusher and the proximalstop.
 19. The method of claim 1, further comprising a step ofwithdrawing the vessel closure device while holding the pusher andproximal stop stationary.
 20. The method of claim 1, further comprisinga step of withdrawing the vessel closure system and moving the vesselclosure system proximal with respect to the proximal stop.
 21. Themethod of claim 1, further comprising a step of placing the hemostaticmaterial within the vessel closure system and then passing the tubulardevice through the vessel closure system.
 22. The method of claim 1,further comprising a step of placing a hydrated sponge within the vesselclosure system and withdrawing the tubular device prior to delivery ofthe hydrated sponge.
 23. The method of claim 21, further comprising astep of advancing a stylet or obturator into the tubular device.
 24. Amethod of facilitating hemostasis of a blood vessel puncture, the methodcomprising: inserting a procedural access sheath through a tissue tractand into a puncture in a blood vessel; providing a vessel closure systemaround the access sheath and at least partially in the tissue tract; andperforming a vascular procedure with the vessel closure system in thetissue tract.
 25. A system for facilitating hemostasis of a blood vesselpuncture, the system comprising: a delivery cannula configured to bereceived around an access sheath; a hemostatic promoting material withinthe delivery cannula for facilitating hemostasis of a blood vesselpuncture when delivered adjacent to the puncture; a proximal stop forpreventing proximal motion of the hemostatic promoting material withinthe delivery cannula when the access sheath is withdrawn proximally fromthe delivery cannula; and a pusher for delivering the sponge materialfrom the delivery cannula.
 26. The system of claim 25, wherein thedelivery cannula is received coaxially around the access sheath.
 27. Thesystem of claim 25, wherein the delivery cannula is receivedasymmetrically around the access sheath.
 28. The system of claim 25,wherein the hemostatic promoting material is an absorbable sponge. 29.The system of claim 25, wherein the hemostatic promoting material is ahydrated and compressed sponge.
 30. The system of claim 25, wherein thedelivery cannula has a staging chamber.
 31. The system of claim 25,further comprising a distal stop or vent.
 32. The system of claim 31,wherein the distal stop or vent is soluable.
 33. The system of claim 31,wherein the distal stop or vent is absorbable.
 34. The system of claim31, wherein the distal stop or vent is removable.
 35. The system ofclaim 25, wherein the access sheath has a bleed-back hole.
 36. Thesystem of claim 25, further comprising a dilator.
 37. The system ofclaim 36, wherein the dilator fits over a guidewire.
 38. The system ofclaim 25, further comprising an introduction port.
 39. The system ofclaim 25, further comprising a stop cock.
 40. The system of claim 25,wherein the delivery cannula has detent features.
 41. The system ofclaim 40, wherein the detent is at least one bump.
 42. The system ofclaim 40, wherein the detent is at least one ratchet.
 43. The system ofclaim 40, wherein the detent is on an inside of the delivery cannula.44. The system of claim 40, wherein the detent is on an outside diameterof the vessel closure system.
 45. The system of claim 25, wherein theproximal stop has a proximal flange to facilitate proper placementwithin the delivery cannula.
 46. The system of claim 25, wherein thehydration of the hemostatic material is performed with a syringe.